Senior Tories were furious after the Foreign Secretary published a 4,000-word Brexit blueprint in a newspaper article and repeated false claims about £350million a week of EU contributions being available for the NHS.

Lib-dem leader Vince Cable said Theresa May should axe Johnson to save her credibility.

Johnson’s tub-thumping vision of Brexit Britain was seen as a disloyal attack on May ahead of her speech in Florence on Friday.

He lamely tweeted he fully backed the PM but many accused him of launching a leadership bid, and Home Secretary Amber Rudd charged him with “backseat driving” and told him to stay clear of managing the Brexit process.

Home Secretary Amber Rudd appeared on The Andrew Marr Show and slapped down Boris Johnson (Image: PA)